Removed URLs back in Google's index

used URL removal tool, but pages are back in SERPs

[macdave]

I've spent a fair amount of time lately removing outdated, moved, and duplicate URLs from Google's index, using a combination of the URL removal tool, robots.txt, and 301s.

Today most, if not all, of the URLs that I removed appear to be back in the index, and some are even appearing in the SERPs.

More troubling still: several URLs that have been disallowed in robots.txt for nearly a year are showing up with caches as recent as last week. (yes, my robots.txt validates)

I could fathom a small rollback, but some of the URLs that are back include pages that have been 301d and/or robots.txt'd for over a year.

Is anybody else seeing this with their sites?

Has this sort of rollback happened before? Should I sit tight or start back in with the URL removal tool?